PHYSICAL AND GEOLOGICAL STRUCTURE 

 OF LORD HOWE ISLAND. 



I. — Physical Structure. 



The geographical position of Lord Howe Island has been already described, 

 and it has been shown that under this name are included a number of 

 outlying rocks. Chief amongst these are the Admiralty Islets to the north ; 

 Mutton Bird Island to the east ; Eabbit or Goat Island, within the Lagoon, 

 on the west ; and the solitary pinnacle, Ball's Pyramid, away to the south- 

 east. 



The outline of Lord Howe Island itself is roughly crescentic, or, as very 

 appropriately termed by Mr. H. T. Wilkinson, J. P., "boomerang-shaped."* 

 The length, as the crow flies, is six or seven miles, or, taking into consideration 

 the inequalities of the surface, probably nearly double that distance. The 

 average width is one mile, but at the southern end of the island it is con- 

 siderably more. The island has been estimated, by Mr. Charles Moore,t to 

 contain 3,220 acres, 2,000 of which would be capable of cultivation. Per- 

 sonally I do not think that much more than a third of this amount will ever 

 be fit for the agriculturist, and then only under certain conditions. 



On approaching from seaward its bold, and in many places, rugged outline 

 becomes apparent ; whilst the close and intricate growth of the vegetation 

 on the hill slopes obscures its really heavily timbered condition. 



Lord Howe Island is practically formed of three high volcanic ridges, the 

 most striking physical features of which, says X ^-fi'- H. T. "Wilkinson, "are the 

 ]g>ountains known as Mount Gower and Mount Ledgbird. The former rises 

 in cliffs from the sea to an altitude of 2,8iO feet and the latter to a height 

 of 2,504 feet, together forming the southern and south-eastern portion of 

 the island and presenting a coast-line of rugged cliffs inaccessible from 

 the sea." The most northerly of these masses forms the northern ex- 

 tremity of the island, and is known as the North Ridge; the central 

 mass forms Mount Lookout ; and the southern, and by far the largest is 

 composed of the two large hills before mentioned, with a few subsidiary 

 eminences, such as the North Hummock and Intermediate Hill. These 

 form the back-bone, as it were, of this most interesting spec of oceanic 

 land, aptly termed the " Madeira of the Pacific," § and are visible at sea 

 for a distance of at least fifty miles. The intermediate depressions are formed 

 of low undulating rises ; and the shore frontages, when not precipitous, are 

 flat and usually open, but sometimes like the low rises densely wooded. 

 Nearly two-thirds of the west coast, or the concave side of the boomerang, 



* Report on the Geology of the Island, Lord Howe Island. Report on Present State, 

 &c., p. 4. 



t Hill's Lord Rowt Island, Loc. cit., p. 17. 



J Op. cit., p. 4. 



§ The Island of Lord Howe. "The Madeira of the Pacific." By "Linnajus" (12 mo. 

 Sydney, 1882). 



